System for depositing liquid material onto a substrate

ABSTRACT

A machine controlled by a computer for depositing a liquefied electronically-interactive material on a sheet or support card, which includes: a base ( 1 ) to support the mobile bed ( 2 ) which is moved longitudinally (Y) by means of a worm screw ( 20 ) whose movement is controlled by a computer, and for the support and fixing of the said support sheet or card “S” on which the layer of electronically-interactive material is to be formed; a bridge above the said base with a transversal shaft ( 30 ) which also has a worm screw and whose movement is also controlled by the said computer, in which the transversal shaft ( 30 ) moves the said distribution unit for the electronically-interactive material to be deposited ( 3 ) in an orthogonal direction (X).

This is a Divisional Application of application Ser. No. 10/500,298,filed Jan. 31, 2005, now U.S. Pat. No. 7,757,628, of Cesare FUMO, JozefVODOPIVEC entitled A SYSTEM FOR DEPOSITING ELECTRONICALLY INTERACTIVELIQUEFIED MATERIAL ONTO A SUPPORT SURFACE, which is a National StageApplication filed under §371 of PCT Application No. PCT/IT02/00780,filed Dec. 11, 2002, published as WO 2003/061357 A1, the entiredisclosures of which are hereby incorporated by reference.

The object of this invention is a method for the formation of a layeringof electronically-interactive material.

TECHNICAL FIELD

By the term electronically-interactive material, we mean any kind ofmaterial which is capable of electronically interacting both in anactive sense, such as through conductivity, or in a negative sense, suchas through insulation, and does not exclude other parameters such as thetypical on/off function which characterizes micro-processors.

The invention is used preferably, but not exclusively, for the formationof a layering of electronically interactive material, such as in: themanufacture of electronic circuit boards; the creation of screens with alayer of electronically-interactive material to project images from aflat screen to create displays, which may also be flexible, directlyincorporating a computerized system which does not exclude the functionof a microprocessor with both organic and non-organic material,including the function of intelligence which may or may not beartificial, similar to cerebral functions; and also visualization ornon-visualization with different grades of variable luminosity materialsby means of electronically induced phenomena which cover the entirerange of the spectrum.

BACKGROUND ART

According to the current state of the technology, the formation of alayering, either composed of a single layer or a number of layers, iscarried out by either mechanical, chemical or photo-chemical methods.The techniques of layering with mechanical systems are slow and not verysuitable for the miniaturization and precision which modern electronictechniques need to acquire.

For example, in order to create electronic circuit boards, which is oneof the main, although not exclusive, uses of this invention, eitherphotographic or photo-engraving techniques are used, which are farsuperior to mechanical systems.

In spite of this, modern technology requires techniques which are morerapid and efficient, and which also have miniaturization and precisioncapacities superior to those achieved up until now, if possible.

It is well known that, even with photo-engraving techniques, since aphoto-sensitive layer has to be engraved, it is not possible to createdesigns and miniaturized circuits below a certain dimension. That is, itis not possible to go below certain values, which are determined by theminimum distance between two engravings, otherwise it would make thethin layer between them unstable because, if it is too thin, it could beeasily detached or ruined. As a general rule, an acceptable value forthe ratio of the distance between, one engraving and another and thethickness of the layer is>1. In fact, if the ratio were less than 1, theheight of the section of the layer would be greater than the width, sothe risk of breakage and a resulting short circuit between two adjacentcircuits would be high.

DE-19817530A discloses a process and device for the production of athin-multilayer structure.

U.S. Pat. No. 3,661,304 discloses a pressure impulse apparatus forinitiating formation of fluid drops such as ink in high speed printing,wherein the drops are selectively placed on a paper web, providing aprimary liquid supply at a constant pressure and starting means forapplying a higher pressure impulse, the starting means including anauxiliary liquid supply.

Aim Of The Invention

The aim of this invention is to overcome the aforementioned drawbacksand to allow a layer of electronically-interactive material to berapidly and quickly formed on a surface, having maximum precision evenwith the smallest of designs and an extremely low cost.

EXPLANATION OF THE INVENTION

The problem is overcome according to characteristics described below.

ADVANTAGES

The advantages obtained with the present invention solution are thefollowing:

-   -   Speed of the process.    -   Maximum simplicity.    -   Maximum precision.    -   Maximum miniaturization of the structures designed and        integrated in the layer.    -   Maximum reliability, safety, robustness and duration of the        layering.    -   Overall reduction of manufacturing costs.    -   Respect for the environment with the elimination of all waste        materials or pollutants.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages will be shown in the following descriptionand attached drawings of a preferential application of the solutionaccording to the present invention, the details of which are intended tobe exemplary and not limiting.

FIG. 1 is a schematic view of a mechanical solution of an applicationmachine for the formation of a layering of electronically-interactivematerial on a support sub-layer, such as in the manufacturing of anelectronic circuit board.

FIG. 2 is a three-dimensional schematic view of a feeding system of adistribution unit for the material used for the formation of thelayering of electronically-interactive material.

FIG. 3 is a view of the distribution unit for the material used for theformation of the layering of electronically interactive material.

FIG. 4 is a schematic front view of the various components of thedistribution unit of the system according to the present invention.

FIG. 5 is a three-dimensional schematic view of a machine which embodiesthe system for the formation of a layering of electronically-interactivematerial according to this invention.

DETAILED DESCRIPTION OF THE SOLUTION ILLUSTRATED IN THE DRAWINGS

With reference to FIG. I, the formation of the layer ofelectronically-interactive material is carried out according to aninnovative technique compared with previous technology, as follows:

-   -   A support (a board of plastic material S, for example) is        positioned on a mobile bed 2, where the movement of the mobile        bed 2 is controlled and programmed by a microprocessor according        to a given coordinate (Y).    -   Above, there is a distribution unit for punctiform jets of the        liquefied material to be deposited (3) in order to form the        layer on the support (S). The distribution unit is s programmed        to move transversally in a controlled manner by a        microprocessor, similar to that of a traditional inkjet printer;        with the distributor having a number of nozzles for the        distribution of points the equivalent of pixels, which are able        to cover a certain area equal to n×d, where “n” is the number of        nozzles which are sprayed in line, and “d” is the distance along        the line from one nozzle to another, with a layout, for example,        along three lines alternately disposed, 1, 2, 3, for a length of        70 mm.    -   The forward progress of the underlying support is in steps of 70        mm, up to the complete deposit on the surface of the support in        question (S).

FIG. 2 illustrates a feeding system of the liquefied material (which maybe colored, for example, with conductive powder in suspension in thevarious containers with a respective electroinduced vibration mixer)which comes from a main container 4 with a cover for loading.

This container has two tubes for the liquefied material: one is a feedline 41 for feeding by means of a solenoid check valve 410 to a pressureequalizer and regulator 5 which will be described in detail in thesuccessive operation, and the other is a return line 71 from a recoveryand recycling container of the same liquefied material 7, the functionof which will be described later.

In this description, the liquefied material means the material used forthe formation of the layering of electronically-interactive materialused to cover the support or plate of plastic material “S”.

From the bottom of the pressure equalizer and regulator 5, there is apipe 53 which leads to the bottom of a buffer 6 with an upper airchamber “A”. The liquid to be -deposited settles in the lower part “L”,where there are pipes which take it to a nozzle chamber forming adistribution means for point-type sprays (31) which forms thedistributor. The buffer 6 is suitable, therefore, to contain theliquefied electronically-interactive material “L.”, while the upper airchamber “A” acts as a pressure compensator, that is as a damper, able toincrease or reduce according to the emission and/or consumption of theliquefied Material and, therefore, increase or reduce the request formaterial from the intermediate pressure equalizer and regulatorcontainer (5).

The buffer 6 is positioned above and is joined to the distribution meansfor point-type sprays (31). Also, the pressure equalizer and regulator 5may move upwards and downwards parallel to the up and down movement ofthe distribution means for point-type sprays (31) and the buffer 6 onguide carriages 52. The pressure equalizer and regulator may also befinely regulated in height with respect to the height of the buffer (6)and the distribution means for point-type sprays (31) so that it mayregulate the pressure to be either higher or lower according to thedifference in level and according to the principle of communicatingvessels, with the pressure variation induced by impeding the principleof communicating vessels by means of the presence of the air chamber “A”in the buffer 6. In this way, by being able to regulate the pressure tobe either higher or lower according to the programmed value by means ofcomputer control with a microprocessor, the highest functionality isachieved.

It thus becomes possible to comply to the following conditions accordingto the program:

i. start distribution at the start of the transversal movement accordingto “X” with a distribution pressure p1;

ii. vary the pressure immediately afterwards to a value p2, where p2<p1,with repetition of the cycle for every transversal movement ofdistribution-deposit “X”; and

iii. vary the distribution again to a value of p3, so that p3>p1, for acleaning operation of filters where the material passes so as to carryout a maintenance cycle during a non-operational phase, that is, whenmaterial is not being deposited according to “i” or “ii”.

According to FIG. 4 which schematically illustrates the distributionunit 3, we can see that, at the side of the distribution means forpoint-type sprays (31), on one side there is an ultra-violet lighttransmitter 34 which has the function of polymerizing the fluiddistributed on the surface of the support material (S), with the liquidbeing distributed in a form to be polymerized due to the action ofultra-violet rays. On the opposite side there is an ultra-sonic distancesensor 32 which detects the distance of the underlying support (S) fromthe depositing bed and transmits the respective data to the processor sothat, according to the program, it brings it closer, takes it furtheraway or holds it at the same distance.

There is also a television camera 33 to the side to view the surface ofthe support zone subject to the deposit in question, both for finetuning by means of reference points according to a well known techniqueand for checking the correct distribution, depositing, regularity of thecovering, etc.

According to FIG. 5, we can see a three-dimensional schematic view of amachine which includes all of this-equipment in order to use the system.The machine has a base 1 which includes the electric and computerizedelectronic system, with a control computer therefor, and which also hasthe function of supporting the mobile bed 2 which is movablelongitudinally by means of worm screws 20, the rotation of which iscontrolled by the computer. The support panel “S”, such as an electroniccircuit board (in plastic material, for example), on which the layer ofelectronically-interactive material is to be formed, is placed on thebed.

A further transversal worm screw 30, the rotation of which is controlledby the computer, is positioned above the mobile bed (2). Thistransversal screw 30 carries the distribution unit 3 as described.

The system for feeding the liquefied material is connected laterally tothe distribution unit (3).

The feeding system is carried out, as already stated, in a controlledway by means of the three containers 4, 5 and 6 with their respectivepiping.

At the back, block 340 forms the ultra-violet ray generator which feedsthe ultra-violet ray transmitter 34.

Going back to the main feed chamber 4 and cover 40, it must be madeclear that it also has the return pipe 71 which comes from a lateraltank 7 fixed at the side of the mobile bed 2, in order to be coveredduring the washing phase of the distribution means for point-type sprays(31) during the non-operational phase of washing the filter with ahigher pressure p3.

In this case, the fluid, which is fed for the washing phase, which isneither polluted or damaged, is recovered by the tank from below thenozzles in the distributor means for point-type sprays (31), and takenby means of the pipe 71 to the main container 4.

All three of the containers 4, 5 and 6 have a vibration unit inside tokeep the liquid constantly in motion during the feeding operation, inorder to keep the suspended substance, which is heavier than the liquid,uniformly distributed (e.g. copper powder for the conductivity of thematerial, pigments for the insulating material, etc.)

The ultra-violet (UV) ray device 34 advantageously works at roomtemperature and, because it heats up, it is cooled down at the same timeaccording to a controlled temperature by suitable equipment which ispart of the machine. In this way, the polymerization of the depositedmaterial is carried out at room temperature without damaging thematerial or the support, and without compromising the functionality ofthe entire depositing unit (3).

The distribution nozzles for the material to be polymerized by means ofthe distribution unit for point-type sprays (31) are advantageouslyconformed to supply punctiform (pixel-by-pixel) sprays equal to 1 pixelat a time in logical succession.

There are one or more rows of distribution nozzles. More rows of nozzlesor distributors may be foreseen in order to deposit different materials.

An example of different materials could be the following, for example:

-   -   conductive material;    -   insulating material; and    -   covering or protective material.

A further advantage is that the system includes the

activation or shut-down of the ultra-violet ray polymerization device(34) in a controlled way to make the following possible:

-   -   the direct polymerization immediately after being, deposited, or    -   to fix it.

1. A system for depositing liquefied material onto a support surface,the system comprising: a distribution unit comprising nozzles whicheject the liquefied material onto the support surface; and a feedingsystem which feeds the liquefied material to the distribution unit,wherein the feeding system comprises: a main container which stores theliquefied material; a recovery container which recovers the liquefiedmaterial ejected from the nozzles; a return line which transports theliquefied material from the recovery container to the main container; atleast one feed line which transports the liquefied material from themain container to the distribution unit; and a regulator disposed on aliquefied material path between the main container and the distributionunit, wherein the regulator comprises a moveable liquefied materialcontainer, wherein a movement of the moveable liquefied materialcontainer and the liquefied material therein regulates a distribution ofpressure between the regulator and the distribution unit, thus alteringa pressure in the distribution unit and altering an ejection pressure ofat least one of the nozzles.
 2. The system according to claim 1, furthercomprising: a mobile bed which supports the support surface, wherein therecovery container is laterally spaced from a side of the mobile bed. 3.The system according to claim 1, wherein the return line comprises atube and the at least one feed line comprises at least one tube.